Ok, I know... everybody has had their go at a version of the extruder feeder for the Ultimaker 2. I have used a customized version for a while and now there even is the UM2+ version as an upgrade available. So why another one...?
Well I personally like the Bondtech concept a lot where the filament is captured and driven from both sides. It gives less deformation on the filament, thus less friction in the bowden tube and less chance on grinding. Also I think it should be a very good option for flex filaments but I have not tested this personally. One note before you continue to read, although this is my 6th version with many tweaks, this is still a work in progress.
The good thing is that you can print all the parts and only need some cheap (eBay) gears and MR85 ball bearings which will set you back a whopping €10,-
Next to the printed parts you will need the following:
I printed the case parts with 30% infill 0.1mm layer which is fine, the lever and pusher I did with 100% infill and 0.1mm layer height.
Only the lever needs support to build plate on in Cura, the rest is printed without support.
I added an internal support to the lever which can easily be removed by placing it on an opening and using a small driver to hit it from the top. The support can than be removed from the side. Also the pusher has support, if you push a sharp knife in the side where the gap is it can easily be removed.
Well not yet. I made several snapshots from the design which should explain everything.